Indicator for radiotubes



Dec. 29, 1931 w. M. STONE INDICATOR FOR RADIOTUBES Filed March 9. 1931 V INVENTOR Warren M. Ed one WITNESS:

H] ATNEY Patented Dec. 29, 1931 PATENT? OFFICE WARREN M. MONE, OF CAIEDEN, NEW JERSEY -mmcaron. non. RADIOTUBES Application filed March '9,

dising used tubes for new, and in various other particulars confusing the buying public by the type of tube sold.

The present invention is directed to means for so sealing a tube that when purchased 0 by the purchaser, it will be a guarantee that the tube is a new tube. It comprises a covering for and spaced from the tube, composed of air-tight material of such nature as to be affected by continued internal heat, asfor instance a wax-coated paper or a sheet material of the nature of paper, which would be discolored by internal heat or any other .type of covering material which would have an external appearance varied from normal by such internal heat.

The invention is directed to other objects and possesses other features of novelty and advantage, some of which, together with the foregoing, will be hereinafter more fully set forth. V

In the drawings:

Figure 1 is a view of one type of seal shown pagtly in elevation and partly broken away, an

Figure 2 is a fragmentary view of a seal of slightly different physical construction.

As shown at Figure 1, a radio tube of conventional type is illustrated. It is wellkuown, of course, that radio tubes differ widely in size and shape, and it is, therefore, obvious that the seal employed upon such tubes will vary accordingly, and the seal shown at 11 at Figure 1 or at 11' at Figure 2 is merephysically formed to correspond to the l shape of the tube 10. Seals for other shapes of tubes will vary according to the shape of the tube.

The tube is composed of some sheet material and is formed to correspond to the shape of the tube with some means inherent 1931. Serial No. 521,065.

in the seal itself for spacing it away from the tube. One such means is shown in the groove 12 which is projected as a ridge upon the interior of the seal and makes contact throughout its entire circumference with the outer surface of the tube.

Another type is shown at 13 consisting of inwardly pressed parts but not continuous. Both of these ty es may be employed on the same seal or eithe one may be used exclusively. It is obvious, of course, that some other style of spacing may be employed and the present invention is broad enough in its sco e to cover any type of spacing which may so used.

The seal is preferably constructed in halves molded to conform to the shape of the tube and with an overlap 14 formed upon one of the halves. The overlap is preferably provided with a tab 15 to be engaged by the finger or thumb or both for the purpose of severing the seal.

Instead of constructing the device with the overlap, as shown at Figure 1, the halves may be flanged, as shown at 16 and 17 in Figure 2, in which case one of the flanges would preferably be provided with a tab 18 for the same purpose as the tab'15.

In either case, the normally lower part of the seal may be in the form of a sleeve 19 which will embrace the cap 20 appearing upon the radio tube of ordinary construction. This sleeve 19 is designed to be rigidly and permanently attached to the cap 20 for the purpose which will appear more definitely hereafter.

The material of which the seal 11 is constructed may vary widely. It is probable that some paper-or pulp material will be employed. This material will preferably be air-tight. Such imperviousness may be imparted by coatings applied interiorly or exteriorly of the material. Such coating may take the form of wax upon the exterior, which will melt at a relatively low temperature. The material may also be of such a nature and so chemically treated that an in-' ternal heat will discolor the material. 7

It is the purposeto provide a seal spaced from the tube by such an interval that the heat generated in the ordinary testing of a tube will not affect the seal, but if operated continuously for a period of time greater than that ordinarily employed in testing, will generate such internal eat as to affect the seal, either by having the waxy coating melt and run, or discolor the material of which the seal is constructed. In either case, such change of appearance of the exterior of the seal will be notice to the purchaser that the tube has been used.

Of course, it is understood that so enclosed air-tight, a use of the tube for any continued time would ruin the tube so that the merchant would be loath to take a chance of such use even if the discoloration of the seal would not be notice of such use.

Sleeve 19 is permanently and rigidly attached to the cap 20 for the purpose of necessitating the fracturing of the seal from such sleeve in its removal from the tube. This is for the purpose of preventing the careful removal of the seal from a new tube and replacing a used tube.

The device when so applied will serve as a protection to the purchaser, as well as a protection to the manufacturer, the reputation of whose tubes is seriously impaired by the merchandising of used tubes as new ones..

While there have been examples of the material and treatment of which the seal is constructed and processed, it is to be understood that it'includes not merely such examples, but any type of seal physically or chemically considered which will, by external appearance, disclose the continuation of internal heat and will be of such nature as to prevent removal and replacement.

Of course, the seal herein illustrated and described may be modified and changed in various ways without departin from the invention herein set forth an hereafter claimed.

The invention is hereby claimed as follows:

1. An indicator for radio tubes, comprising an opaque impervious cover attached to but spaced from the tube.

2. An indicator for radio tubes, comprising an opaque shell permanently attached to and removable from the tube only in sections, and composed of material permanently disclosing upon the exterior the previous generation of internal heat.

3. An indicator for radio tubes, comprising an opaque shell of sheet material sealed upon the tube, and composed of material permanently affected by previous internal heat. 4

4. An indicator for radio tubes, consisting of an opaque material associated with the exterior of tube in such manner as to pennanently exhibit the previous continued generation of internal heat.

5. An indicator for radio tubes, comprising a sheet of opaque material treated to be visually changed by heating, said sheet of material, being attached externally to the tube in such manner as to be affected by previous internal heat therefrom.

6. An indicator for radio tubes, comprising a sheet of material chemically treated to be permanently discolored by previous heat, said sheet being attached exteriorly to the tube.

7. A11 indicator for radio tubes, comprising a shell inhering heat variable characteristics and shell conforming to the shape of the tube and spaced therefrom, and means for permanently securing a part of said seal to the base of said tube.

8. An indicator for radio tubes, comprising a shell inhering heat variable characteristics, said shell conforming to the shape of the tube and embodying inherent means for spacing the said shell away from the tube, and means to attach a part of said shell permanently to the base of the tube.

9. An indicator for radio tubes, comprising a shell treated to imperviousness, means to attach the shell permanently to the base of the tube, and material at the exterior surface of the shell permanently visually affected by previous heat. I

10. An indicator for radio tubes, comprising a shell conforming in shape with the tube and spaced therefrom, means inherent in the tube for maintaining such spacing, means for attaching a part of said shell permanently to the base of the tube, and a coating upon the exterior of the shell permanently physically modified by internal heat.

11. An indicator for radio tubes, comprising a shell conforming to the configuration of the tube and spaced therefrom, means inherent in the shell for maintaining the spacing, means to attach a part of said shell permanently to the base of the tube, and chemically applied means possessing the quality of variation of color upon the application of internal heat.

12. An indicator for radio tubes, comprising a shell enclosing and spaced from the tube impervious to air and adapted to confine the generated heat of the tube to such an extent as to ruin the tube upon continued use.

In testimony whereof I have signed my name to this specification WARREN M. STONE. 

